Analysis of Isothermal Solidification Process on Transient Liquid Insert Metal Diffusion Bonding

Study on Transient Liquid Insert Metal Diffusion Bonding of Ni-base Superalloys (part 2)

Abstract

In this report, isothermal solidification process on transient liquid phase insert metal diffusion bonding of Ni-B binary system and Ni-P binary system was investigated.
From experimental results on the isothermal solidification process, it was clarified that this process was controlled by the diffusional process of B and P in the base metal. The activation energy Q and frequency factor Do for diffusion of B and P in Ni obtained were as follows
B in Ni: Q=226 kJ/mol, Do=0.14 m²/s
P in Ni: Q=284 kJ/mol, Do=0.49 m²/s
The complete time of the process can be estimated by equation (1) and (2)
Ni-B system: t^1/2_f=53.8×(2h/D^1/2)…………(1)
Ni-P system: t^1/2_f=26.4×(2h/D^1/2)…………(2)
The isothermal solidification process on Ni base superalloy joints were also examined.
The isothermal solidification process of MM-007, MarM-247, Inconel-713C and Inconel-600 joints with using Ni-15.5%Cr-3.7%B insert metal can be also interpreted by the same theoretical equation applied to the process of Ni-B system.